d4041db120
We're still hearing rare reports of apps running while the system is trying to do surgery on app code/data. To fix this once and for all, start guarding all PackageManager critical sections by freezing and then killing the app before doing surgery. This is done by introducing a new PackageFreezer class which can be used in try-with-resources blocks. It also handles child packages uniformly, and it uses CloseGuard to defensively un-freeze packages if a caller leaks without closing. The set of frozen packages is now maintained outside of PackageSetting to support newly installed packages. Add docs for the various locks and method syntax conventions, including the new "LIF" syntax which indicates the caller is responsible for freezing the package being worked on. Bug: 27698554 Change-Id: I64c4c48123060ccb4d4c50c2fbf3ef223c01e659